Metalworking apparatus



J y 18 194 J. D. BUCHANAQ 2,353,874

METALWOHKING APPARATUS .Filed Nov. 18, 1940 2 Sheets-Sheet l y 1944- J.D. BUCHANAN METALWORKING APPARATUS Filed Nov. 18, 1940 2 Sheets-Sheet 2Patented July 18, 1944 UNITED STATES PATENT OFFICE METALWORKINGAPPARATUS J. D. Buchanan, Burbank, Calif.

Application November 18, 1940, Serial No. 366,027

7 Claims. (Cl. 90--13.7)

The invention relates to metal working apparatus wherein a tool is movedby a follower acting on a pattern, to cause the tool to operate on awork piece and machine it like the pattern. The invention has for anobject to machine the work piece like the pattern with great precision,even though the pattern has a discontinuous contour.

Although it is possible to machine a work piece with a discontinuouscontour by means of an end mill and a dividing head, such work islaborious and time consuming. Also it has been proposed to mount afollower and a cutter on a swinging arm as shown in the patent toLecomte 1,389,835, but here the tool and the follower travel indifferent arcs at right angles to the common axis of the work piece andpattern, so that the movement of the tool is not strictly proportionalto the contour of the pattern, and this lack of proportionality isaggravated at places of sharp discontinuity in the contour of thepattern.

An object of the invention is to machine a work piece different in sizefrom but strictly proportional to a pattern, even though the pattern hasa discontinuous contour, and to effect this in a continuous operation bya machine.

A further object is to provide a machine for maintaining strictproportionality between the position of the tool and the contour of thepattern, for all positions of the follower.

A further object of the invention is to improve the accessibility,removability and adjustability of the component parts of such a machine.

For further details of the invention, reference may be made to thedrawings wherein:

Fig. 1 is a vertical sectional view on line II of Fig. 2, of a machineaccording to the present invention.

Fig. 2 is a plan view of the machine of Fig. 1.

Fig. 3 is a, vertical sectional view on line 3-3 of Fig. 1.

Fig. 4 is an end elevation of the work piece holder of Fig. 2.

Fig. 5 is a perspective view of a typical blank work piece to be tooledby the machine of this invention.

Referring in detail to the drawings, the rad al tool (cutter or grinderI), which is moved under control of the follower 2 acting on the pattern3,

is to fashion or machine the work piece 4 to precisely the same shape asthe pattern 3, but on a smaller scale.

The pattern 3 and the work piece 4 are rotated in synchronism at a slowspeed such as one revolution per minute, while the tool I is driven at ahigh speed; viz. 250 lineal feet per minute.

The rotary tool I and the follower 2 are mounted on a swinging arm 5which is pivotally supported by the adjustable pivot pins 6 and Imounted in standards 8 and 9 respectively arising from the base ID.

The pivotal axis I5 of the arm 5, which is determined by the pins 6 andI, together with the four axes of rotation of tool I, follower 2,pattern 3 and work piece 4, are all parallel to each other.

The pattern 3 is shown as having a contour which is discontinuous asrepresented by the points II and I2, that is the contour of pattern 3changes abruptly at these points. If the follower 2 were substantially apoint instead of being a large disk as herein illustrated and if thevarious parts were not properly correlated as herein provided, the pointfollower on reaching a place of discontinuity in the pattern 3 woulddrop the tool I too fast to make a faithful copy of the pattern. Theinvention provides that the cutter shall be raised and lowered at theproper instant of time with respect to the rotation of the pattern 3 andwork piece 4 by arranging the center I3 of follower 2 on a straight lineI 4 which passes through the axis of tool I and through the axis I5 ofthe pivot pins 6 and I, and by giving the radius of follower 2 a valuesuch that it bears to the radius of tool I the same ratio that thedistance from center I3 to pivot axis I5 bears to the distance from theaxis of tool I to pivot axis I5. A straight line through the axis I5 andtangent to the periphery of the tool I, will also be tangent to theperiphery of the follower 2. However, the working points of the tool Iand the follower 2 may vary from their points of tangency depending uponthe contour of the pattern 3. I also arrange the pivot axis I5 and theaxes of pattern 3 and work piece 4 on a straight line. Also, the axis'ofwork piece 4 and the axis of tool I are at the same distance from pivotI5, and the axis of pattern 3 and the axis I3 of follower 2 are at thesame distance from pivot I5. Hence two similar isosceles triangles areformed, having a common apex at the pivot axis I5, one of themhaving-two equal sides from the pivot axis 5 to the axis of tool I andfrom the pivot axis I5 to the axis of workpiece 4, assuming a base lineto be constructed from the axis of tool I to the axis of workpiece 4,and the other triangle having the two equal sides from axis I5 to theaxis i3'and from axis l5 to the axis of pattern 3, assuming a base linefrom axis I3 to the axis of pattern 3. Also, these two triangles remainsimilar isosceles triangles for all working positions of the swingingarm 5.

This means that as the arm swings up and down, with the follower 2 incontact with the pattern 3, the distance between axis I3- and the axisof pattern 3 always bears to the distance between the axis of tool I andthe axis of work piece 4, the same ratio as the corresponding sides oftheir respective triangles; namely, the distance from axis I3. to I5 tothe distance from the axis of tool I to the axis I5, thelast mentionedratio being the same as the ratio of the wheel 26. Worm wheel 24 issupported by bearing 2! and is mounted on a shaft 28 to which thepattern 3 is fastened by means of key 28.

Worm wheel 26, as shown in Fig. 3, is rotatably mounted on a fixedsleeve 33 secured by p n 3| at the top of standard 32 which arises fromthe base I 0. Inside of sleeve 33 is a hollow sleeve adapter 33 toreceive the work piece 4. Work piece 4 as shown in Fig. 5, is here shownas comprising a shaft 34 having a non-circular or flat portion 35terminating in a threaded end 33. Shaft 34 has integral therewith, ablank disk 31 which is to be cut in the shape of a cam or valve lifterto correspond with the shape of the pattern 3 as shown in Fig. 1.

The bore of adapter 33 is made non-circular to interfit with the flat 35so that the work piece 4 will turn with adapter 33, the latter having anarm 38 as shown in Fig. 4 which is contacted by a bolt 39 mounted on andturning with the gear 26. The threaded end 36 of the work piece 4projects beyond the end of adapter 33 and on this projecting end Iprovide a nut 39 to clamp the work piece 4 to the end of adapter 33. Thework piece 4 is centered by means of an adjustable centering pin 40mounted in the standard 4I arising from base ID at one end of work piece4, and by an adjustable centering of pin 42 at the other end of workpiece 4. Pin 42 is mounted in a latch or swinging arm 43 which ispivotally mounted on the bolt 39, the other end of arm 43 having a latchor cut away portion 44 to ride over and engage a similar bolt 45 alsomounted on gear 23. The arm 43 is held in position on the bolts 39 and45 by means of nuts 46 and 43, on bolt 39, and 41, 41 on bolt 45.

As shown in Figs. 2 and 3, the swinging arm 5 has sides 31 and 68 spacedapart and'forming bearings 49 and 50 for the shaft 5| of a radial cutterI. On shaft BI is mounted a pulley 52 coupled by belt 53 to the pulley54 of a motor 55 which is mounted on an arm 53 secured to arm 5 by boltslike 51. As the motor 55 is on the opposite side of the pivot axis I5from the arm 5 and its parts, the motor 55 acts as a countor-balance forarm 5. The circular disk follower 2 is rotatably mounted on thebifurcated end 58 of the arm 5.

As the arm 5 is supported by the center pins 6 and 1, these pins may beadjusted to vary the transverse position of the arm 5 and the tool I andfollower 2 thereon.

The work piece 4 maybe axially shifted by meansof the center pins 40 and42. Also, the

work piece 4 may be removed from the machine by backing off the screw42, by loosening nuts 45 and 47 and swinging the arm 43 upwardly tolaterally move the pin 42 out of the way, and by pulling the adapter 33and the work piece 4 carried thereby axially out of the sleeve 30, thelatter having a diameter larger than the work piece 4. This provides asimple way for substituting a new blank work piece after the precedingone has been finished.

Follower 2 is removably mounted on a pin or shaft 59 and anotherfollower slightly larger or smaller than the one calculated as above,may be' used to compensate for wear of the tool I or for wear of otherparts of the machine, or to compensate for slight inaccuracies inlocating the axes of the tool I, follower 2, pattern 3 and workpiece 4withiresp ct to the pivot I5.

rotated in synchronism at-aslowspeed such ascne revolution perminute,while the tool I .is driven at a high speedsuch as 250 lineal feet perminute, as above stated, it follows that the b ank workpiece 4 asshownin Fig. 5, is provided with a finished out which is the counter-part ofthe pattern 3 when thepattern 3 and workpiece 4 have made but onerevolution.

The effective length of the follower 2 is of course the length oftheline from its point of contact with pattern 3 to the axis I3, orexpressed differently, from its-point of contact with pattern 3 to thepoint where the axis of follower 2 intersects the straight line I4.Likewise, the effective length'of the cutter I is the length ofthe linefrom its contact with the work piece 4 to the point where ,theaxis oftool I intersects line I 4.

Various modificationsmay be made in the invention without departing fromthe spirit of the claims. For example, the pattern may have any desiredcontour other than that shown, and in fact, its contour may becontinuous instead of discontinuous.

I claim: I

1. Metal working machine comprisin the combination ofa drive shaft, apair of spaced worm gears thereon, a worm wheel for each of said gears,means supporting each of said gears for rotation on substantiallyparallel axes, a pattern coupled to one of said gears, a fixed sleeverotatably supporting the other of said gears, a workpiece holder fittingsaid sleeve, and means removably securing said holder to said othergear, and follower means for tooling the work piece in accordance withsaid pattern.

2. Metal working machine comprising the com bination of a drive shaft, apair of spaced worm gears thereon, a worm wheel for each of said gears,means supporting each of said gears for rotation on substantiallyparallel axes, a pattern coupled to one of said gears, a fixed sleeverotatably supporting the other of said gears, a work piece holderfitting said sleeve, means removably securing said holder to said othergear, means for removably securing in said holder one end of a workpiece smaller in diameter than the inside diameter of said sleeve, meansspaced from said gear for rotatably supporting the other end of the workpiece, a rotatable tool, a movable support therefor adapted to move thetool to contact the work piece between said work holder and said meansfor supporting the other end-of the work piece, and'follower'means formoving said tool support in accordance with said pattern.

3. Metalworking apparatus comprising the combination of a pair of wormgears, means supporting said gears for rotation on parallel axes, acommon drive shaft and worms thereon for said gears, a pattern coupledto one of said gears, a fixed sleeve supporting the other of said gears,said sleeve having a bore larger than a work piece havin a shaft with anintermediate raised portion to be tooled, means at one end of saidsleeve for securing one end of the work piece axially of said sleevewith the raised portion of the Work piece projecting beyond the otherend of said sleeve, and tooling means controlled by said pattern fortooling the raised portion of the work piece.

4. Metal working machine comprising the combination of a drive shaft, apair of spaced worm gears thereon, a worm wheel for each of said gears,means supporting each of said gears for rotation on substantiallyparallel axes, a pattern coupled to one of said gears, a fixed sleeverotatably supporting the other of said gears, a workpiece holder fittingsaid sleeve, means for removably securing one end portion of theworkpiece in said holder coaxially of said sleeve, spaced means forrotatably supporting the opposite end portion of the workpiece, meansremovably securing said holder to said other gear, and follower meansfor tooling the workpiece in accordance with said pattern.

5. Metalworkin machine comprising the combination of a drive shaft, apair of spaced worm gears thereon, a worm wheel for each of said gears,means supporting each of said gears for rotation on substantiallyparallel axes, a pattern coupled to one of said gears, a fixed sleeverotatably supporting the other of said gears, a workpiece holder fittingsaid sleeve, means for removably securing one end portion of theworkpiece in a said holder coaxially of said sleeve, spaced means forrotatably supporting the opposite end portion of the workpiece, meansremovably securing said holder to said other gear, and follower meanscomprising a tool holder supporting a tool for rotation on an axisparallel to the axis of said sleeve for tooling the workpiece inaccordance with said pattern.

6. Metal working machine comprising the combination of a base, a driveshaft on said base, a pair of spaced worm gears on said shaft, 2.

worm wheel for each of said gears, means supporting each of said gearson said base for rotation on substantially parallel axes, a pivot onsaid base, a pattern coupled to one of said gears remote from saidpivot, a fixed sleeve rotatably supporting the other of said gearsadjacent said pivot, a workpiece holder fitting said sleeve, acooperating workpiece support on said base, means removably securingsaid holder to said other gear, an arm pivotally connected to saidpivot, a circular follower at the outer end of said arm arranged to reston said pattern, and a tool holder on said arm for supporting a tool forthe workpiece, said tool holder comprising means for supporting a, toolfor rotation on an axis parallel to a line through the centers of saidsleeve and said workpiece support.

'7. A metal working machine comprising the combination of relativelymovable supports, a pivot therefor permitting movement of one of saidsupports about a common axis, one of said supports supporting arotatable pattern and a rotatable work piece holder on the same side ofsaid pivot, said pattern and said work piece holder being mounted forrotation on centers lying on a straight line through said pivot, afollower for said pattern and a tool for said Work piece holder arrangedon the other of said supports on centers lying on another straight linethrough said pivot, said follower being adapted to rest on said patternand said tool being adapted to rest on a work piece, the point ofintersection of the axis of the tool with said second line and thecenter of the work holder being at the same distance from said pivot,the point of intersection of the axis of the follower with said secondline and the center of said pattern being at the same distance from saidpivot, one of said distances being greater than the other, the ratio ofthe effective length of said follower to the effective length of saidtool being the same as the ratio of the distances of their respectivesaid points of intersection from said pivot, the point where saidfollower is adapted to contact the pattern, and the point where saidtool is adapted to finish the work piece, lying on a straight linethrough said pivot, whereby said tool when guided by said followercontacting said pattern is adapted to traverse the contour thereof toreproduce the same by said ratio.

J. D. BUCHANAN.

